Electron discharge device and its circuits



1949. L. w. PARKER 2,477,644

ELECTRON DISCHARGE DEVICE AND ITS CIRCUITS Filed Dec. 8, 1945 I 2 Sheets-Sheet 1 g A I II E zip-54 J T' A 4 1 A x I N V EN TOR.

100/5 W P/l/PKf/P A T TORNE' Y 1949- w. PARKER 2,477,644

ELECTRON DISCHARGE DEVICE AND ITS CIRCUITS Filed Dec. 8, 1945 2 Sheets-Sheet 2 28 4 j 2? 26 V 59 [000099 MQ:

1N VEN TOR. 100/3 144' PAR/Y5? CBY Patented Aug. 2, 1949 iiST-ATL-S FF 16E YYEIZECTRON DISCHARGE DEVICELAND "ITS CIRCUITS L cLouisWwParker; Jackson Heights, N. Y assignor "3 .Claims. 1

.:.;.-This mvention-irelates toselectrondischarge devices. andrtheirrcircnitsaand particularly to high reduencywwides-bantl iampliileia employing such .11: devices.

.1 In: trial-operation at; amplifiers at: the-hi frequencies, the inter-electrodeecapacities of the electron discharge devices employedtherein beiii-come:amimportarit-iactoniending. to lower the 1s. input andaautputrm edances and consequently .e-loiwering.thengain. ottsuch amplifierss The ire-1 a. cque'ncies. a-tiiwhicliethesei-iefiectstoccurt vary with theipar-tieulamtuba:andmircuiterrangement, but 1. =.the loweting' oiilemciency oi-suclramplifiers, due toethese-iintersleleottodecapacities,is usually quite innniobiect' oifithe.cprescntinvention is'the pror1 uisiorr err am impnovede electron. discharge device amend particularlymna adapted .for. distributed am- 1 bllfication 'for :use atsthe ehighe'r frequencies.

...i.Another object ot-thapresentinvention is the a pronounced inttherangeabove-onemegacycle.

I, ti); Federal Telephone and Radio Corporation, 1" .Ne'iit York,v N. .Y aeorporation of Delaware agpn'licatiohz-December 8; 1945,:SeriaLNmr633e804 anode and cathodesis substantially in shunt across the outputsthereof; 'nT-here isLalso. an input capacity 5 in shuntlaorcs'ssthennput ofitube 2, that is,betweenhthe,grldandcathode oftube 2;" These twocapacities .4;.a'n.d -.5...cause agsubstantial de- In accordance. withcone' aspect of this inventicn, the gain of such amplifier is. increased by splitting .ithe tinput. and-cutput capacities of the amplifien'tubes in:sina1l-..parts 'andinserting small .inductances betweemthe split parts; Fig. 2 .represents;.the equivalent circuit" of..what is thereby .accomplishedif Itiwill b'eiseeh from Fig.

. atnat.whatisprcducedbythereregoing is equivalent to a. 1ow;-passT';filtericircuit; As in low ....pass 1 filters .theloadiimpedanceincreases as. the

T individual ,capacities'are "loweredif Consequently,

by'spliting uplthe inputgand output capacities in the amplifierjtubesi. andi-inserting'inductances thereb'etween, a ,jiigheriloadi impedance is produ'ced', thus'resulting ingreater gain for the'am- Referring now tO'ZQFig. 3, in1whic1'r twostages of an .amplifierrare 'illustrated:.thereiare two second'tubei""'Eacli ofisaid tubes includes acathode," grid" and *armda'fbutunlikeistandard grids and ancdes';th egrids' orqtube s'fi' and? are split into a-phirality' ofseparate sections ii-which are "connected "together hy'seriesdumped inductance coils 3.--Simi1arly theianodesaresplit' into a plurality of-separater-plates otsections I'll which are connected togetherby-seriesdumped inductance made iuisaidfaiiiialifieri inacc'ordance with one 7' jaspectof'riiy invention;

F1233 is ralf'scheniatfcidiagrarrf of aptwo -stage amplifier embodymamyimzention ..-,;,Fig...4 is aidiaeramniati'c' planview or a tube constructed in'faccordance with my invention;

and

Fig. 5 is a broken-away detail, taken in side "elevation? of a portlon' of the tub'e illustrated in Fig. 4.

In corrzentionalramplifieizsyzthe inter-electrode capacities of the tubesemployed therein limit the .gaintthe. effect of saidjtc'apacities being greater *rithe' hi'gher the 'frequency atwhich the amplifier is:nperaltedf For exampie; in the "conventional amplifier iilustrated in'Fig."1;"which-includes two tubes l and 2 coupled together by a condenser 3, the output capacity of tube I, designated by the coils ll:- In-theembodiment illustrated-the anode of tube'fi-isseparated into two plates; whereas the anode of tube is separated in'the-three plates.

It will be ofcourseappreci-ated thatmany more plates maybe employed and'that the number of plates and tubes ofntherseparate stages do not necessarily have tobe tif-thetv same amount. This also holdsior :the numbei' of sections into which the grids are split? ItWillbe--recognized that tubes 6 and T-areicoupledtogether bythe' equivalent of theloW-tpa-Ss filter'circuit shown in Fig.

2, inr-whictr'the capacities are" relatively small due to :thezbreak -up of'the. anodes and grids. into small portions "forming;- small inter-electrode ca- -pacities Witirthe other' elements nithe tubes.

" The insertion of.inductances in the electrodes together :with the intereelectrode capacity, introduce a small; butupdssibly appreciable time delay during the travel. of. energy fromaone, end of an numeral 4, consisting of the Capacity between the 55 electrode to its other end, since substantial values of L and C are i n volved and. time delay is proportional to /LC. In order to compensate for this time delay, the input l2 to tube 6 is applied through a lead l3 to one end (the lower end) i l of the grid. The signal energy is taken from the anode 6 at the end 15 thereof, opposite the end it, which i adjacent to end IA of the grid. In tube 7 the signal energy is applied to end ll of the grid and is taken off the anode at op posite end l8 thereof. It will be seen that the anodes are provided with two leads through the envelope, the signal energy being taken off at one end of the anode with the plate resistor 59 and the positive side of a source of anode potential 23 applied at the other end thereof. Two leads may also be provided for the grids, for example, for the purpose of connection of the grid leak 2i and a source of biasing voltage 22.

In conventional type tubes, the inter-electrode capacity is not split up. Furthermore the inductance inherent in the electrodes is so small as to be practically of no effect. Anodes are usually made in the form of solid plates whose inductive reactance is extremely small. While the turns of the grid wires would tend to have some appreciable inductance, the supporting rods on which the grid wire is wound and to which the grid wire is welded, serves to reduce this inductance to an insubstantial amount by shorting these turns.

In contrast, a tube embodying my invention is illustrated in Figs. 4 and 5. This tube 23, has an envelope 2 3, within which is mounted a cathode 25, of the indirectly heated type and whose exterior is substantially rectangular in cross section. The cathode is surrounded by a grid 26 also rectangular in cross section. On opposite sides of the wide faces of the grid 26 are arranged the halves of the screen grid and suppressor grid 2'? and 28 respectively, the opposite halves of which are connected together by wires 29 and 30 respectively. The anode 3| is also comprised of two halves 32 and 33 respectively which are connected together by wires or leads 34.

Both the grid 26 and the anode 3| are split up into small portions or sections which are connected together by lumped constant inductance coils. For example (see Fig. each half of the grid 25 consists of a plurality of sections arranged vertically one above the other and insulated from each other. Each section of the grid is welded to a U-shaped member 35, which is mounted on insulating support 36, consisting of a plurality of beads 31, held together by a wire 38. A plurality of lumped constant inductance coils 3e ar each connected in series between a separate pair of adjacent U-shaped conductors 35. The inductances 39 are staggered and arranged on opposite ends of the grid structure so as to occupy the minimum of space and be separated as much as possible from each other. Likewise each half of the anode 3! is vertically divided into a plurality of separate plates or sections 40, adjacent pairs of which are connected together in series with one of a plurality of lumped constant inductance coils 4|. Each of the anode halves may consist of two or more plates depending upon the specific conditions encountered. The inductance coils 4| are arranged toward the middle of each half of the anode 3|. To prevent interaction between the inductance coils 39 and 4|, and to provide'some measure of inter-electrode shielding, a plurality of shields 42 is arranged at the ends of the anodes and extend between the suppressor and screen grids and the coils 39. The values of inductance coils 39 and 4| are such as to provide a substantial inductive reactance at the operating frequencies of said electron discharge device.

In certain instances the leads to the electrodes in the tubes, and the socket prongs for the tubes may have a substantial capacity. To include this capacity as part of the low pass filter, inductances would have to be arranged on both sides of this capacity. Therefore if such capacity exists and as in Fig. 3, inductances are arranged within the tubes, where one or more additional inductances will have to be arranged outside the tubes, as for example, inductances 43 and 44.

It will of course be understood that while I have described the specific details of an embodiment of my invention, numerous changes may be made therein, as will be apparent to those versed in the art. Accordingly, while I have described above the principles of my invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation on the scope of my invention as defined in the accompanying claims.

I claim:

1. An electron discharge device comprising'an envelope, a cathode, grid and anode mounted within said envelope, said grid and anode each having portions between which there is a substantial inductance, thereby introducing a progressive time delay between one end of said grid and an opposite end thereof, and a progressive time delay between one end of said anode and the opposite end thereof, a lead to a given end of said grid extending through the envelope and lead to an end of said anode opposite the end thereof adjacent said given end of the grid.

2. An electron discharge device according to claim 1 further including a second lead to said anode to the end thereof adjacent said given end of the grid, said second lead extending through the envelope.

3. An electron discharge device comprising an envelope, a cathode, grid and anode mounted within said envelope, said grid and anode each comprising a plurality of sections, lumped inductance means connecting the anode sections in series and having a value of inductance providing a progressive phase shift between opposite ends of said anode, lumped inductance means connecting the grid sections in series and having a value of inductance providing a progressive phase shift between opposite ends of said grid, input means connected to a given end of said grid for impressing a signal on said given end of the grid, and output means connected to an end of said anode opposite the end thereof adjacent said given end of the grid.

LOUIS W. PARKER.

REFERENCES CITED The following referenlces are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,981,058 Marconi Nov. 20, 1934 2,033,112 Carlisle Mar. 10, 1936 2,194,555 Keale Mar. 26, 1940 

